Apparatus and method for decoding four states with one pin
US5023483A · kind A · utility
4Cited by
7References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 27, 1989 |
| Grant date | Jun 11, 1991 |
| Priority date | — |
| Expiry date | Jun 27, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F1/22
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
According to one aspect of the invention, a novel control circuit is coupled to a pin at a circuit node. The circuit node has a particular default condition of one of two logic states. The control circuit stores the default value and subsequently attempts to drive an alternate logic state onto the pin. The circuit then reads the logic state at the pin to determine if there has been a change of logic state registered. If a change has been registered, then the existence of a third condition or fourth condition is indicated, depending upon the default logic state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.